Location update procedure when roaming from a first communication service domain to a second communications service domain

ABSTRACT

The invention relates to a location update procedure in a mobile communications system ( 150 ) having at least one first communications service domain ( 100 ) and at least one second communications service domain ( 110 ). The mobile subscriber ( 140 ) is allowed to register in said first communications service domain. A location update request is received at a network element ( 170 ) of the communications system, and a subscription restriction information is received at this network element, said subscription restriction information indicating, whether a roaming restriction for a roaming into the second communications serice domain applies for the mobile subscriber. The subscription restriction information is evaluated, and the location update procedure is performed depending on the evaluation. The invention relates further to a corresponding network element ( 170 ), home subscriber data register ( 160 ), user equipment ( 140 ) and computer program.

[0001] The invention addresses the field of mobile communications. Itrelates to a method, device and computer program for performing alocation update procedure for a mobile subscriber. It relates inparticular to a roaming of a mobile subscriber from a 2^(nd) generationsystem domain like a Global System for Mobile Communication GSM domainto a 3^(rd) generation system domain like a Universal MobileTelecommunication System UMTS domain, or vice versa.

BACKGROUND OF THE INVENTION

[0002] In mobile communications systems, a location update procedure isperformed to allow a roaming of a subscriber from one to another servicedomain. E.g., if a mobile subscriber, who is registered in a servicedomain of his Home Public Land Mobile Network HPLMN operator, leaves hishome country and moves to a service domain operated by a Visited PublicLand Mobile Network VPLMN operator, the location update procedure isperformed to allow for the international roaming. Details about serviceaccessibility can be found, e.g., in 3G TS 22.011 v.3.3.0, 3rdGeneration Partnership Project; Technical Specification Group Servicesand System Aspects; Service accessibility (Release 1999).

[0003] The term ‘roaming’ describes as well a scenario, wherein themobile subscriber has currently not accessed his HPLMN domain, e.g.because the terminal is at present switched off, but accesses whilebeing located in a VPLMN domain the VPLMN domain by switching histerminal on.

[0004] For UMTS, it is planned to use GSM Subscriber Identity ModulesSIMs in a UMTS mobile terminal to get access to service. However, thecurrent standards for roaming in UMTS and GSM as well as the legalrequirements set by individual national countries, differ with respectto roaming for the subscriber. UMTS subscribers will be entitled tonational roaming, as it is foreseen that the UMTS networks initiallyconsist of small islands only. To provide more frequent access toservice, the subscriber shall have the possibility to register tonetworks on a national basis in addition to international roaming.

[0005] GSM subscribers are usually not entitled to national roaming.Nevertheless, the GSM subscriber using a dual mode, e.g. GSM-UMTS,mobile terminal shall be able to access both GSM and UMTS systems in hishome country as well as abroad.

[0006] Currently, it is not possible to allow for a differentiatedaccessing of dedicated service domains according to the outlined roamingrules, as there is no means to distinguish GSM subscribers from UMTSsubscribers. The reason is that for the 3GPP Release 99 and beyond, bothGSM and UMTS apply the same security mechanisms as stated in 3G TS33.102, v.3.6.0, 3rd Generation Partnership Project; TechnicalSpecification Group Services and System Aspects; 3G Security; SecurityArchitecture, clause 6.8.1.1.

[0007] Problems occur for roaming cases involving a Home Public LandMobile Network HPLMN operator and a Visited Public Land Mobile NetworkVPLMN operator if both of them are running GSM and UMTS networks in thesame country and are using the same Mobile Network Codes MNCs for theirnetworks. Such a scenario is likely in particular in the early days ofUMTS introduction when operators run their UMTS networks from anadministration point of view as extensions of their existing GSMnetworks.

[0008] If a GSM subscriber being served by his HPLMN operator's UMTSnetwork moves, he can get out of coverage of his HPLMN operator's UMTSnetwork but in coverage of another UMTS operator's network. According tonational roaming agreements for UMTS he is granted service by thevisited UMTS network. If getting out of coverage of the visited UMTSnetwork, he is served by the same network operator's GSM network.Although there might be no roaming agreement for GSM existing betweenthe GSM networks, the GSM subscriber cannot be prevented from roaming tothe foreign GSM network.

SUMMARY OF THE INVENTION

[0009] It is an object of the invention to provide a method, device andcomputer program for a differentiation of access entitlements of amobile subscriber to dedicated service domains of a mobilecommunications system.

[0010] This is solved by the teaching of the independent claims.

[0011] A mobile communications system has at least one firstcommunications service domain, e.g. a GSM domain, and at least onesecond communications service domain, e.g. a UMTS domain. A mobilesubscriber is allowed to access said first communications servicedomain, which is e.g. a service domain of his HPLMN operator. A locationupdate request is received at a network element, preferably a MobileSwitching Centre MSC or a Serving GPRS Support Node SGSN, of thecommunications system. A skilled person understands easily that thenetwork element can be any further network node or part of any furthernetwork node of the communications system. E.g., the inventive functioncan be performed as well in an HLR.

[0012] For performing a location update procedure for the mobilesubscriber, a subscription restriction information is received at thenetwork element. The subscription restriction information indicates,whether an access restriction for accessing the second communicationsservice domain applies for the mobile subscriber. The subscriptionrestriction information is evaluated at the network element, and thelocation update procedure is performed depending on the evaluation.

[0013] Advantageously, the provision of a subscription restrictioninformation allows for a differentiated treatment of mobile subscribersusing dual mode, e.g. GSM/UMTS, terminals with respect to roaming.Operators can design their UMTS networks according to island conceptsfor areas having a high population in an efficient way, whilesimultaneously providing in general a broad service coverage to theircustomers via GSM. Differentiated roaming agreements can be set withother operators. Individual roaming requirements given by national lawscan easily be fulfilled. Furthermore, the mobile subscribers can benefitfrom dedicated roaming possibilities and access entitlements in terms ofoptimised service coverage.

[0014] Operators running both GSM and UMTS networks will be able toprovide to their customers services allowing to distinguish between GSM,UMTS, as well as intersystem roaming services.

[0015] According to the invention, a home subscriber data register, e.g.a Home Location Register HLR is adapted to store a subscriptionrestriction information assigned to stored data of a mobile subscriber.The subscription restriction information indicates at least one accessrestriction that applies to the mobile subscriber for accessing acommunications service domain of a mobile communications system.

[0016] Advantageously, the HPLMN operator keeps by storing thesubscription restriction information in his HLR control of therestrictions. Furthermore, easy administration and modification of thesubscriber restrictions are possible. Advantageously, the operator canuse the same Mobile Network Code MNC for both his GSM and UMTS portionof his PLMN, e.g. by simply storing an indicator in the networkadministration data belonging to the respective service areas giving thecorresponding access type, e.g. GSM or UMTS.

[0017] A user equipment of a mobile subscriber is adapted to store asubscription restriction information that indicates at least one accessrestriction that applies to the mobile subscriber for accessing acommunications service domain of a mobile communications system. Theuser equipment can be any terminal like a GSM-, GPRS- or UMTS-phone,-laptop or -adapter. The user equipment can comprise a SubscriberIdentity Module SIM card that stores the subscription restrictioninformation.

[0018] Advantageously, the storing of the subscription restrictioninformation in the user equipment can reduce the administrative effortof the operator because a central database administering the restrictioninformation is not needed. Furthernore, the subscription restrictioninformation can easily be displayed to the mobile subscriber.

[0019] It should be noted that the signalling of the subscriptionrestriction information can be performed by a network element, e.g. HLR,by a user equipment, or by both of them. Advantageously, an operator candecide for the latter case in particular if there are differences in therestriction information, which one of the signalling sources getspriority. Furthermore, the restriction information of the two signallingsources can be evaluated in a complementary way.

[0020] Furthermore, the invention can be realised by a computer program,which is loadable into the internal memory of a digital processing unit,comprising software code portions adapted to control the steps of thedescribed methods, when the computer program is executed on the digitalprocessing unit. Therefore, servers that are by means of the computerprogram adapted to perform the inventive method can easily representnetwork elements according to the present invention.

[0021] Preferred embodiments of the invention are described in thedependent claims.

[0022] A location update is performed if the evaluation of thesubscription restriction information indicates that an accessing of thesecond communications service domain is allowed for the mobilesubscriber.

[0023] A location update request is rejected if the subscriptionrestriction information evaluation indicates that an accessing of thesecond communications service domain is not allowed for the mobilesubscriber.

[0024] In a preferred embodiment, an error information is sent inresponse to the location update request if the request is rejected, saiderror information indicating an access restriction as a reason for therejection. Therefore, redundant re-tries of a location update requestthat has already been rejected can be avoided.

[0025] In a further preferred embodiment, the subscription restrictioninformation is received within the location update request sent from auser equipment of the mobile subscriber. Advantageously, the receivingnetwork node can evaluate, whether a corresponding accessing and/ orroaming of the mobile subscriber is allowed, without requesting saidinformation from a further network node, e.g. from an HLR. Therefore,signalling traffic can be avoided.

[0026] In another preferred embodiment, the subscriber data informationis requested from a home subscriber data register, e.g. an HLR, and thesubscription restriction information is received within subscriber datainformation sent from the home subscriber data register. Advantageously,there is no need to store the subscription restriction information inthe user equipment. Instead, the information is under the control of theHPLMN operator. Advantageously, signalling traffic is minimised by usingthe transmission of subscriber data information, e.g. by a correspondingMobile Application Part MAP message, which is performed for the purposeof location update, also for the transmission of the subscriptionrestriction information.

[0027] In a further embodiment, the subscriber restriction informationcomprises an access network type restriction information indicating anaccess network type restriction. Access network types are e.g. GSM,GPRS, UMTS or Wireless LAN.

[0028] In another embodiment, the subscription restriction informationcomprises a frequency band restriction information indicating afrequency band restriction. Depending on the used radio accesstechnique, mobile communications systems can use different frequencybands, also called frequency areas, to provide radio access. Preferably,frequency bands are symbolized by a significant frequency, e.g. 800 MHz,1800 MHz, 1900 MHz (all GSM), and 2400 MHz (UMTS).

[0029] In a further embodiment, the subscription restriction informationcomprises a Public Land Mobile Network PLMN type restriction informationindicating a PLMN restriction. PLMN types are e.g. a HPLMN or a VPLMN.Alternatively, individual operator identifiers can be PLMN types aswell.

[0030] In another embodiment, the home subscriber data register HLR isadapted to send on request a subscriber data information comprising asubscription restriction information that applies to the mobilesubscriber. Therefore, a network element like a MSC or SGSN canretrieve—based upon a location update request received from a userequipment—the corresponding subscription restriction information inorder to evaluate whether the subscriber is entitled to the requestedcommunications service domain access.

[0031] In a further embodiment, the user equipment is adapted to send alocation update request comprising the subscription restrictioninformation, if the user equipment determines a change of its locationarea.

[0032] In another preferred embodiment the computer program is stored ona computer readable medium like a CD-ROM, a floppy disc, optical disc orhard disk. Therefore, a good physical portability of the controlsoftware is provided, i.e. upgrades of network elements represented byservers can be performed in an easy way.

BRIEF DESCRIPTION OF THE FIGURES

[0033] The figures show:

[0034]FIG. 1 a simplified HPLMN and its served communications servicedomains,

[0035]FIG. 2 a simplified HPLMN and VPLMN and a hybrid coveragecommunications service domain,

[0036]FIG. 3 a message flow for a HPLMN-controlled location updateprocedure with allowed UMTS access,

[0037]FIG. 4 a further message flow for a HPLMN-controlled locationupdate procedure for a GSM subscriber accessing a GSM network,

[0038]FIG. 5 a structure of a ‘insert subscriber data’ message,

[0039]FIG. 6a a 1 bit embodiment for a subscription restrictionparameter SRP,

[0040]FIG. 6b a 2 bit embodiment for a SRP,

[0041]FIG. 6c a 4 bit embodiment for a SRP,

[0042]FIG. 6d a 6 bit embodiment for a SRP for multiband operationrestriction

[0043]FIG. 7 a further message flow for a HPLMN-controlled locationupdate procedure for a GSM subscriber requesting access to a UMTSnetwork, and

[0044]FIG. 8 a further message flow for a user-equipment controlledlocation update procedure for UMTS access with UMTS SIM indication.

DETAILED DESCRIPTION

[0045] A subscription parameter can be present in both the subscriberdata stored in the HLR as well as on the SIM or in the user equipmentitself. It can be used for two different types of roaming servicesallowing network operators (HPLMN and VPLMN) to allow and reject accessto their network. The serving MSC is able to determine the access typethe subscriber used.

[0046] One type of roaming services refers to roaming restriction due tosubscription restriction via the HPLMN. Preferably, a currently unusedparameter “Subscription restriction” as described in 3G TS 23.008v.3.5.0: 3rd Generation Partnership Project; Technical SpecificationGroup Core Network; Organisation of subscriber data (Release 99), clause2.4.10, is enhanced to cover possible scenarios. According to theinvention, this parameter is downloaded to the visited MSC/VLR (VMSC) atlocation update. The VMSC grants or rejects access to a roamingsubscriber depending on the settings of this parameter and the type ofaccess the subscriber uses. Additionally, if access is denied, aspecific error, i.e. error code, can be generated and sent to the mobilestation of the subscriber, e.g. to trigger network reselection.

[0047] This approach can also be used to allow/reject GSM/UMTS roamingin the HPLMN.

[0048] Another type of roaming services refers to roaming restrictiondue to subscription restriction (VPLMN). The UMTS SIM (USIM) contains aparameter giving the same range as the one described in the aboveparagraph. Preferably, the parameter is introduced as a capability andconfiguration parameter (3G TS 21.111, v. 3.3.0: 3rd GenerationPartnership Project; Technical Specification Group Terminals; USIM andIC Card Requirements, release 1999, clause 10.1). At location update,the VMSC checks the value of this parameter and grants/rejects access toa roaming subscriber depending on the settings of this parameter and thetype of access the subscriber uses. If access is denied, a specificerror can be generated and sent to the mobile station of the subscriber,e.g. to trigger network reselection.

[0049] In the following, the invention and its embodiments are describedwith reference to the figures.

[0050]FIG. 1 shows simplified a mobile communications system 150comprising a Home Location Register (HLR) 160 storing subscriber data ofmobile subscribers, a Mobile Switching Centre/Visitor Location Register(MSC/VLR) 170 performing, e.g., switching tasks and by means of locationupdates registrations of mobile subscribers in communications servicedomains, and a Base Station System (BSS) 180 providing radio access tothe mobile communications system 150. The mobile communications system150 represents a Home Public Land Mobile Network (HPLMN) of an operator.The HLR 160 is connected to the MSC/VLR 170. The MSC/VLR 170 isconnected to the BSS 180.

[0051] In alternative embodiments, the MSC/VLR can be a pooled networknode. The VLR can be implemented by a separate network node. The BSS canbe represented by a Radio Network Controller RNC. The MSC, orrespectively the MSC/VLR can be a Serving GPRS Support Node SGSN.

[0052] The mobile communications system provides communications servicesin different coverage areas, i.e. communications service domains. Thereare communications service domains providing GSM coverage 100, 130.Other communications service domains provide UMTS coverage 110, 120. Auser equipment (MS) 140, e.g. a mobile terminal, that is registered insuch a domain communicates via the BSS 180 with the communicationssystem 150.

[0053] The invention applies to both circuit-switched and/or packetswitched domains. Furthermore, a skilled person can easily derivefurther appropriate communications service domain types, i.e. accessnetwork types, than GSM or UMTS, e.g. a Wireless Local Area Network Type(Wireless LAN) or a Bluetooth™ network type.

[0054] If a mobile subscriber using the MS 140 moves from onecommunications service domain to another, a location update procedure isperformed in order to register the MS 140 for the purpose of serviceprovisioning in the newly entered communications service domain.Technical compatibility of the MS 140 provided, it depends onsubscription restrictions valid for the mobile subscriber, whether theMS 140 is served in the new domain, i.e. whether the MS 140 is allowedto access the new domain.

[0055] A location update procedure can be performed not only due tophysical movement of the MS 140, but, e.g., as well for the purpose ofinitial registration of the MS 140 in the mobile communications system150, if the MS is switched on.

[0056]FIG. 2 shows simplified a mobile communications system comprisinga HPLMN 250 and a Visited Public Land Mobile Network (VPLMN) 290. HPLMNand VPLMN can be operated by different operators. The HPLMN 250comprises a HLR 260. The VPLMN 290 comprises a MSC/VLR 270 and a BSS280. The MSC/VLR 270 is connected to the HLR 260 and the BSS 280. TheVPLMN 290 serves a hybrid coverage communications service domain 200,i.e. within the domain 200 both GSM and UMTS communications services areprovided. A MS 240 communicates via the BSS 280 with the mobilecommunications system.

[0057] Technical compatibility provided, a MS 240 that is registered bymeans of GSM in the mobile communications system can request a locationupdate in order to change the access network type to UMTS, e.g. due to atrigger of an application that requires a higher bandwidth. On the otherhand, a location update request is possible for the purpose of changingthe registration from UMTS to GSM.

[0058]FIG. 3 shows a message flow for a HPLMN-controlled location updateprocedure with allowed UMTS access. A user equipment (UE) 300 sends alocation update request message 330 (via a corresponding BSS or RNC, notshown) requesting UMTS or GSM access to a MSC 310 (or alternativelySGSN), which transmits a corresponding location update request message340 to an HLR 320 that is located in the HPLMN. The HLR 320 determines,whether any subscription restrictions apply for the mobile subscriber.In the shown example, UMTS access is allowed 350. In response to thelocation update request 340, the HLR 320 sends an Insert Subscriber Datamessage 360 comprising an indication that UMTS access is allowed to theMSC 310. The MSC 310 checks the access 370 and registers the UE 300 inthe requested UMTS domain, and it acknowledges the location update tothe HLR 320 by sending a Insert Subscriber Data Response message 380.Furthermore, it acknowledges the performed location update by means of aLocation Update Response 390 sent to the UE 300.

[0059]FIG. 4 shows a message flow for a HPLMN-controlled location updateprocedure for a GSM subscriber accessing a GSM network. A user equipment(UE) 300 of a GSM subscriber sends a location update request message 400(via a corresponding BSS or RNC, not shown) requesting GSM access to aMSC 310 (or SGSN accordingly), which transmits a corresponding locationupdate request message 410 to an HLR 320 that is located in the HPLMN.The HLR 320 determines, whether any subscription restrictions apply forthe mobile subscriber. In the shown example, UMTS access is not allowed420. In response to the location update request 410, the HLR 320 sendsan Insert Subscriber Data message 430 to the MSC 310 indicating thatUMTS access is not allowed. The MSC 310 checks the access 440 andregisters the UE 300 in the requested GSM domain, and it acknowledgesthe location update to the HLR 320 by sending a Insert Subscriber DataResponse message 450. After a Location update response message 460 isreceived from the HLR 320, the MSC 310 acknowledges the performedlocation update to the UE 300 by means of a Location Update Response470.

[0060]FIG. 5 shows a structure of an Insert Subscriber Data message 500.It comprises subscriber data 510 and a subscriber restriction parameter520, called as weLl subscription restriction parameter 520. Preferably,the Insert Subscriber Data message is a MAP message. Details about MAPmessages can be found in 3G TS 29.002 v. 3.7.2, 3rd GenerationPartnership Project; Technical Specification Group Core Network; MobileApplication Part (MAP) specification (release 99).

[0061] In an alternative embodiment of the invention, the SRP isrequested and/or sent via separate messages each.

[0062]FIG. 6 illustrates in some examples the possible structures andvalues of the subscription restriction parameter SRP. Preferably, theSRP indicates an access network type restriction as shown in FIG. 6a bythe values of an 1 bit SRP parameter. If the bit value is ‘0’, UMTSaccess, i.e. an access to the UMTS access network, is not allowed. Ifthe bit value is ‘1’, UMTS access is allowed. In another embodiment, theSRP parameter value ‘0’ means that GSM access is not allowed, while fora value ‘1’ GSM access is permitted.

[0063] In the case of a location update acknowledgement message, e.g.Location Update Response message 390, 470 or Insert Subscriber Data 360,430, the 1 bit SRP can easily be understood as an acknowledgement flagin response to a dedicated location update request, e.g. with SRP=‘1’having the meaning ‘acknowledged’ and SRP=‘0’ having the meaning ‘notacknowledged’.

[0064] Furthermore, the SRP parameter can easily cover more than twodifferent access network types, e.g. by using the appropriate number ofbits.

[0065]FIG. 6b shows a preferred embodiment of a 2 bit structure of theSRP. This structure allows for the differentiation of roamingrestrictions in terms of access network types (GSM, UMTS) and networktypes (HPLMN, VPLMN). E.g., the SRP value ‘01’ indicates that in theHPLMN GSM access is allowed, while the mobile subscriber is in the VPLMNentitled to UMTS access. In other words, the table indicates for HPLMNand VPLMN the allowed domains. In this way, an entry ‘UMTS allowed’excludes GSM, i.e. GSM is not allowed. In a further embodiment, an entry‘UMTS allowed’ includes the permission for GSM, i.e. includes ‘GSMallowed’. Preferably, operators of HPLMN and VPLMN can agree incorresponding roaming agreements about such rules for interpretation ofthe SRP parameters.

[0066]FIG. 6c illustrates a 4 bit structure of the SRP. The first bitrepresents the entitlement for UMTS in the HPLMN, the second bit theentitlement to GSM in the HPLMN. The third bit refers to UMTS in VPLMN,the fourth bit to GSM in VPLMN. Preferably, the bit value ‘0’ means ‘notallowed’, while the value ‘1’ indicates ‘allowed’. By using the schemeoutlined in FIG. 6c, a mobile subscriber can be entitled to more thanone access network type. In such a case, different rules can apply—e.g.dependent on operator agreements or the contract of the mobilesubscriber with the HPLMN operator, or the current load situation in thecorresponding network. Nevertheless, operators can set their preferencesas default. E.g., if a the SRP indicates by a value ‘1111’ anentitlement to a total roaming, the default can be ‘GSM preferred’.‘UMTS preferred’ or ‘no default’. It should be noted that apart from theexemplary values other possible values of the SRP not shown in the tablecan be valid restriction indications as well.

[0067]FIG. 6d shows an embodiment, wherein the SRP is used to indicatemultiband operation restrictions that are valid for a mobile subscriber.Multiband operations refer to roaming between domains serving differentfrequency areas or frequency bands, e.g. the roaming of a subscriberfrom GSM 900 to GSM 1800.

[0068] The SRP of FIG. 6d has a 6 bit structure. Bit 1 refers to thefrequency band 450 MHz, bit 2 refers to 800 MHz etc. Usually, thefrequencies of 450 MHz to 1900 MHz refer to GSM systems, while thefrequency area 2400 MHz is used for UMTS. Preferably, a bit value ‘1’indicates an entitlement for roaming into a communications servicedomain serving the given frequency area, while the value ‘0’ indicatesthat a mobile subscriber is not allowed to register in such a domain.

[0069] Apart from the SRP value schemes as outlined in the FIGS. 6a to 6d, any combinations and derivations are possible both for SRP structureand values.

[0070]FIG. 7 shows a message flow for a HPLMN-controlled location updateprocedure, wherein a GSM subscriber requests access to a UMTS network.The user equipment (UE) 300 sends a location update request message 730(via a corresponding BSS or RNC, not shown) to a MSC 310 (oralternatively SGSN) requesting UMTS access. The MSC 310 transmits acorresponding location update request message 740 to the HLR 320 that islocated in the HPLMN. The HLR 320 determines that there is asubscription restriction for the mobile subscriber 750, i.e. that themobile subscriber is not entitled to UMTS access. In response to thelocation update request 740, the HLR 320 sends an Insert Subscriber Datamessage 760 indicating by means of a SRP that UMTS access is not allowedto the MSC 310. The MSC 310 checks the access 770 by evaluating thesubscription restriction information received as SRP within the InsertSubscriber Data message and rejects the location update request bysending an error information indicating ‘access not allowed’, i.e.indicating a roaming restriction as a reason for the rejection, both tothe HLR 780 and the UE 790.

[0071]FIG. 8 shows a user-equipment controlled location update procedurefor UMTS access. The user equipment (UE) 300 uses a UMTS SIM card (USIM)that stores the subscription restriction information valid for themobile subscriber. The UE requests UMTS access by sending a LocationUpdate ‘USIM’ request 820 to the MSC 310 (or SGSN accordingly). Thelocation update request comprises a subscription restrictioninformation, preferably by means of a subscription restriction parameterSRP, which is evaluated by the MSC 310 (or SGSN). Afterwards, the MSC310 (or SGSN) performs the requested location update and acknowledges itby means of a Location Update Response message 830 to the UE 300.

[0072] Without being limited to, the invention can be used preferably inall communications systems as defined by 3GPP in the release 99 as wellas in all future releases thereof. In particular, this includes UMTSnetworks, core networks, GSM networks and the corresponding userequipment, as well as Wireless LANs and Bluetooth™ networks and userequipments.

1. Method of performing for a mobile subscriber a location update procedure in a mobile communications system (150) having at least one first communications service domain (100; 200) and at least one second communications service domain (110, 120, 130; 200), wherein the mobile subscriber is allowed to access said first communications service domain (100; 200), and wherein a location update request (330; 400; 730; 820) is received at a network element (170; 270) of the communications system (150), characterised in that a subscription restriction information (360; 430; 760; 820) is received at the network element, wherein said subscription restriction information (360; 430; 760; 820) indicates, whether a restriction for accessing the second communications service domain (110, 120, 130; 200) applies for the mobile subscriber, the subscription restriction information (360; 430; 760; 820) is evaluated, and the location update procedure is performed depending on the evaluation.
 2. Method according to claim 1, wherein a location update is performed if the evaluation of the subscription restriction information indicates that an accessing of the second communications service domain (110, 120, 130; 200) is allowed for the mobile subscriber.
 3. Method according to any preceding claim, wherein the location update request is rejected (780, 790) if the subscription restriction information evaluation indicates that an accessing of the second communications service domain (110, 120, 130; 200) is not allowed for the mobile subscriber.
 4. Method according to claim 3, wherein an error information (780, 790) is sent in response to the location update request if the request is rejected, said error information indicating an access restriction as a reason for the rejection.
 5. Method according to any preceding claim, wherein the subscription restriction information is received within the location update request (820) sent from a user equipment (140; 240; 300) of the mobile subscriber.
 6. Method according to any preceding claim, wherein subscriber data information is requested from a home subscriber data register (160; 260), and wherein the subscription restriction information is received within subscriber data information (360; 430; 760) sent from the home subscriber data register (160; 260).
 7. Method according to any preceding claim, wherein the subscription restriction information comprises an access network type restriction information indicating an access network type restriction.
 8. Method according to any preceding claim, wherein the subscription restriction information comprises a frequency band restriction information indicating a frequency band restriction.
 9. Method according to any preceding claim, wherein the subscription restriction information comprises a public land mobile network type restriction information indicating a public land mobile network restriction..
 10. Network element (170; 270) adapted to perform the method according to any of the claims 1 to
 9. 11. Home subscriber data register (160; 260) adapted to store a subscription restriction information assigned to stored data of a mobile subscriber, said subscription restriction information indicating at least one access restriction that applies to the mobile subscriber for accessing a communications service domain (100, 110, 120,130; 200) of a mobile communications system (150).
 12. Home subscriber data register (160; 260) according to claim 11, adapted to send on request a subscriber data information (360; 430; 760) comprising a subscription restriction information that applies to the mobile subscriber.
 13. User equipment (140; 240; 300) of a mobile subscriber adapted to store a subscription restriction information, said subscription restriction information indicating at least one access restriction that applies to the mobile subscriber for accessing communications service domain (100, 110, 120, 130; 200) of a mobile communications system (150).
 14. User equipment (140; 240; 300) according to claim 13, adapted to send a location update request comprising the subscription restriction information (820), if the user equipment (140; 240; 300) determines a change of its location area.
 15. Computer program, loadable into the internal memory of a digital processing unit, comprising software code portions adapted to control the steps according to any of the claims 1 to 9, when the computer program is executed on the digital processing unit.
 16. Computer program according to claim 15, wherein the computer program is stored on a computer-readable medium. 